Câu hỏi của Con gái thời hiện đại ngại gì FA

Question

Bài tập: So sánh:

a, $\dfrac{12}{49}\&\dfrac{13}{47}$

$b,\dfrac{64}{85}\&\dfrac{17}{35}$

$c,\dfrac{19}{31}\&\dfrac{17}{35}$

(Gợi ý: a,b,c: Phân số chung gian)

\(d,\dfrac{67}{77}\&\dfrac{73}...

Mashiro Shiina · Accepted Answer

a)$12< 13;49>47$ $\Rightarrow\dfrac{12}{49}< \dfrac{13}{47}$ b)$\dfrac{64}{85}>\dfrac{43}{85}\Rightarrow\dfrac{64}{85}>\dfrac{1}{2}$ $\dfrac{17}{35}< \dfrac{17}{34}\Rightarrow\dfrac{17}{35}< \dfrac{1}{2}$ $\Rightarrow\dfrac{17}{35}< \dfrac{64}{85}$ c) $\dfrac{19}{31}>\dfrac{16}{31}\Rightarrow\dfrac{19}{31}>\dfrac{1}{2}$ $\dfrac{17}{35}< \dfrac{17}{34}\Rightarrow\dfrac{17}{35}< \dfrac{1}{2}$ $\Rightarrow\dfrac{17}{35}< \dfrac{19}{31}$ d) $1-\dfrac{67}{77}=\dfrac{10}{77}$ $1-\dfrac{73}{83}=\dfrac{10}{83}$ $\dfrac{10}{77}>\dfrac{10}{83}\Rightarrow\dfrac{67}{77}< \dfrac{73}{83}$ e)$1-\dfrac{456}{461}=\dfrac{5}{461}$ $1-\dfrac{123}{128}=\dfrac{5}{128}$ $\dfrac{5}{461}< \dfrac{5}{128}\Rightarrow\dfrac{456}{461}>\dfrac{123}{128}$Câu trả lời: a)$12< 13;49>47$ $\Rightarrow\dfrac{12}{49}< \dfrac{13}{47}$ b)$\dfrac{64}{85}>\dfrac{43}{85}\Rightarrow\dfrac{64}{85}>\dfrac{1}{2}$ $\dfrac{17}{35}< \dfrac{17}{34}\Rightarrow\dfrac{17}{35}< \dfrac{1}{2}$ $\Rightarrow\dfrac{17}{35}< \dfrac{64}{85}$ c) $\dfrac{19}{31}>\dfrac{16}{31}\Rightarrow\dfrac{19}{31}>\dfrac{1}{2}$ $\dfrac{17}{35}< \dfrac{17}{34}\Rightarrow\dfrac{17}{35}< \dfrac{1}{2}$ $\Rightarrow\dfrac{17}{35}< \dfrac{19}{31}$ d) $1-\dfrac{67}{77}=\dfrac{10}{77}$ $1-\dfrac{73}{83}=\dfrac{10}{83}$ $\dfrac{10}{77}>\dfrac{10}{83}\Rightarrow\dfrac{67}{77}< \dfrac{73}{83}$ e)$1-\dfrac{456}{461}=\dfrac{5}{461}$ $1-\dfrac{123}{128}=\dfrac{5}{128}$ $\dfrac{5}{461}< \dfrac{5}{128}\Rightarrow\dfrac{456}{461}>\dfrac{123}{128}$

Nguyễn Thị Giang Thanh · Answer

$a,\dfrac{12}{49}< \dfrac{12}{47}< \dfrac{13}{47}\Rightarrow\dfrac{12}{49}< \dfrac{12}{47}$ b, Ta có: $\dfrac{17}{35}=\dfrac{51}{105}$ $\dfrac{64}{85}>\dfrac{64}{105}>\dfrac{51}{105}\Rightarrow\dfrac{64}{85}>\dfrac{51}{105}$ hay $\dfrac{64}{85}>\dfrac{17}{85}$ c,$\dfrac{19}{31}>\dfrac{17}{31}>\dfrac{17}{35}\Rightarrow\dfrac{19}{31}>\dfrac{17}{35}$ d, $\dfrac{67}{77}+\dfrac{10}{77}=1$ $\dfrac{73}{83}+\dfrac{10}{83}=1$ $\dfrac{10}{77}>\dfrac{10}{83}\Rightarrow\dfrac{67}{77}< \dfrac{73}{83}$ e, $\dfrac{456}{461}+\dfrac{5}{461}=1$ $\dfrac{123}{128}+\dfrac{5}{128}=1$ $\dfrac{5}{461}< \dfrac{5}{128}\Rightarrow\dfrac{456}{461}>\dfrac{123}{128}$Câu trả lời: $a,\dfrac{12}{49}< \dfrac{12}{47}< \dfrac{13}{47}\Rightarrow\dfrac{12}{49}< \dfrac{12}{47}$ b, Ta có: $\dfrac{17}{35}=\dfrac{51}{105}$ $\dfrac{64}{85}>\dfrac{64}{105}>\dfrac{51}{105}\Rightarrow\dfrac{64}{85}>\dfrac{51}{105}$ hay $\dfrac{64}{85}>\dfrac{17}{85}$ c,$\dfrac{19}{31}>\dfrac{17}{31}>\dfrac{17}{35}\Rightarrow\dfrac{19}{31}>\dfrac{17}{35}$ d, $\dfrac{67}{77}+\dfrac{10}{77}=1$ $\dfrac{73}{83}+\dfrac{10}{83}=1$ $\dfrac{10}{77}>\dfrac{10}{83}\Rightarrow\dfrac{67}{77}< \dfrac{73}{83}$ e, $\dfrac{456}{461}+\dfrac{5}{461}=1$ $\dfrac{123}{128}+\dfrac{5}{128}=1$ $\dfrac{5}{461}< \dfrac{5}{128}\Rightarrow\dfrac{456}{461}>\dfrac{123}{128}$

Chúng tôi đề xuất

Tài nguyên

Ứng dụng mobile

Bảng xếp hạng

Các khóa học có thể bạn quan tâm

Yêu cầu VIP